MailGuard email service provider (ESP)
According to Live Direct Marketing's daily Tranco top-1M scan (September 20, 2026), MailGuard is the email service provider (ESP) for 93 domains — 0.01% of 638,158 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
Key facts
- 93 domains in the Tranco top-1M use MailGuard (0.01% of SPF-publishing domains).
- Snapshot date: 2026-09-20 — recomputed every day.
- Strongest TLD: .com.au (53.8% of its domains).
- Most co-used service: Unknown / Other.
- Directory category: email security gateway.
Why MailGuard appears in this category
MailGuard — Australian email security gateway.
We classify it as a email security gateway from include: mechanisms in the SPF record matching a maintained provider rule. This is infrastructure attribution from public DNS, not evidence of a direct contract or exclusive use.
MailGuard is an email service provider identified through SPF include mechanisms embedded in email authentication records. It appears across the Tranco top-1M website ranking, indicating active use in production email infrastructure.
MailGuard's presence concentrates in the smaller-to-mid-sized operator segment rather than the largest global brands, with particular density in Australian (.com.au) domains. For email practitioners evaluating sender reputation and authentication, this regional footprint—often appearing alongside other alternative or lesser-known providers—suggests MailGuard serves a specific geographic or market niche rather than mainstream consumer-facing platforms.
Where MailGuard sits in the Tranco ranking
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 0 | 0.0% |
| Top 10,000 | 0 | 0.0% |
| Top 100,000 | 6 | 6.5% |
| Top 1,000,000 | 86 | 92.5% |
| Unranked | 1 | 1.1% |
Top-level domain split
| TLD | Domains | Share | |
|---|---|---|---|
| .com.au | 50 | 53.8% | |
| .com | 18 | 19.4% | |
| .au | 13 | 14.0% | |
| .org | 3 | 3.2% | |
| .co.il | 2 | 2.2% | |
| .net.au | 2 | 2.2% | |
| .co.uk | 1 | 1.1% | |
| .eu | 1 | 1.1% | |
| .global | 1 | 1.1% | |
| .net | 1 | 1.1% |
What MailGuard users also use
Cross-tabulated from the same daily snapshot — the other email services seen on the same 93 domains.
| Type | Service | Domains | Share of MailGuard users |
|---|---|---|---|
| Mailbox | Unknown / Other | 62 | 66.7% |
| Mailbox | Microsoft 365 | 22 | 23.7% |
| Mailbox | Google Workspace | 3 | 3.2% |
| Mailbox | Proofpoint Essentials | 1 | 1.1% |
| Mailbox | Proofpoint | 1 | 1.1% |
| Mailbox | Sophos Email | 1 | 1.1% |
| ESP | Mailchimp | 17 | 18.3% |
| ESP | Amazon SES | 16 | 17.2% |
| ESP | Zendesk | 11 | 11.8% |
| ESP | SendGrid (Twilio) | 9 | 9.7% |
SPF Authentication and Regional Relevance
MailGuard is detected in live email infrastructure primarily through its SPF include mechanisms, the standard protocol for delegating outbound mail authorisation. The concentration of its presence in .com.au domains positions it as a notable factor in Australian email routing and reputation assessment. Organisations sending to or through Australian recipients should ensure their SPF records correctly reference any MailGuard mechanisms their ESP has configured, as misalignment can degrade authentication pass rates in that region.
See the full MailGuard data page (KPI cards, trend, sample domains) →
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Frequently asked questions
What is MailGuard and should I test deliverability against it?
MailGuard is an email service provider used primarily by mid-sized and regional operators, especially in Australia. If your recipient base includes Australian users or .com.au domains, including MailGuard in your SPF and authentication testing is prudent; for broader international audiences, it ranks lower in priority.
How many domains use MailGuard?
93 domains in the Tranco top-1M use MailGuard as their email service provider (ESP) as of September 20, 2026 (0.01% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
Is MailGuard common enough to affect email deliverability testing?
MailGuard accounts for 0.01% of SPF-publishing domains in the top 1M. Whether you should seed a test mailbox there depends on how much of your audience it represents — the co-usage table above shows the services it appears alongside most.
Which countries or TLDs use MailGuard most?
MailGuard's largest TLD is .com.au (53.8% of its domains); it appears across 11 TLDs in total.